Add ATK_RELATION_NODE_PARENT_OF relationship.
Add ATK_RELATION_NODE_PARENT_OF relationship.

Bug #569427.

collects/atk,GNOME/at-spi2-core,Distrotech/atk,GNOME/at-spi2-core,GNOME/at-spi2-core,collects/atk,Distrotech/atk,Distrotech/atk